Heat dissipation from an integrated circuit (IC) chip or die during operation is typically an important issue, especially as the density of IC devices on a die continues to increase. Also, many devices now have combinations of high-power transistors and low-power transistors formed on a same die. Such high-power transistors tend to produce more heat than low-power transistors. Further, more system-on-chip configurations are being used. Thus, there are often a wide variety of IC devices on a same die. Some of the IC devices can handle and/or put out much more heat than nearby or neighboring devices on the same die. Hence, the reliability and effectiveness of heat dissipation for a packaged IC die may greatly affect the reliability and/or performance of an IC chip during operation.
Many die packages 22 have an exposed die pad surface 24, as shown in FIG. 1 for example. Typically a die 26 is attached to or bonded to a die pad 28 to improve heat transfer from the die 26 via the die pad 28. An exposed die pad 28 is often soldered to a heat sink member 30, as shown in FIG. 2 for example, or other metal components on a printed circuit board (PCB) 34 to provide a primary heat transfer path from the die 26 to the heat sink 30 via the die pad 28. The heat sink 30 in FIG. 2 is a metal rivet that extends through the PCB 34. Many die pads 28 of die packages 22 are thin to help reduce package size (e.g., package thickness). As a result, many die pads 28 are flexible and easily deformed (like a diaphragm). In such cases, it has been found that the forces exerted on a die pad 28 by solidifying solder 36 may be great enough to cause delamination between the die pad 28 and the die 26 where the die 26 is supposed to be attached to the die pad 28. Such delamination may greatly reduce the heat transfer efficiency and hinder the thermal path for cooling the die 26 via the die pad 28. It would be preferred to reduce the probability that a die pad 28 may be delaminated from a die 26 or deformed by a solder attachment procedure due to solder solidification forces.